I had a shooting mate visit this morning. He has a RPR in .223.
I mentioned the cold weather(~7 degrees at sunrise) seems to make the RPR hard to pull the bolt back, and he looks confused.
His rifle was a bit stiff when new, and has loosened up with use.
He picks mine up(mag is full), and tries to pull the bolt back, and it takes a lot of effort.
Even 2 rounds in the mag is sufficient to make the bolt hard to pull back.
He initially wondered if the bolt wasnt lubed, but I explained that around every 50 rounds, in addition to a clean, I remove the bolt, and swab the chamber out repeatedly with those cotton chamber swabs, then clean the bolt, and then lightly grease all wearing surfaces with bolt grease.
So we dump all of the rounds out of the mag, and the bolts comes back easily.
Looking at it a bit further, we note the lips on the Ruger-supplied P-Mags are deforming when the mag-follower is putting any pressure on them (when there are rounds in the mag), and causing the lips to splay out and up, and so fouling the bolt.
These mags are just on 6 months old, and havent been left in a hot car or anywhere they could be exposed to excessive heat.
See attached image.
The Ruger P-Mag is on the left, and if you look down beside the shoulder on the RH side, you can see a score mark where the bolt is dragging across the lip.
The P-Mag on the right is an MDT-TAC P-Mag, and much stiffer lips, due to the single stack feed.
The AI metal mags, and the MDT-TAC P-Mags, all work perfectly.
However, in just 6 months, the RPR mags are pretty much stuffed.
My intial bright idea was to lightly sand the lips where they are fouling the bolt, but then we realised that 'give in the design of the lips will keep it happening until I run out of lip to sand away!
My mate was really surprised, and hadnt seen the same on his .223 mags.
I do keep my mags full most of the time, but havent seen any warnings against this, and it isnt the springs that are losing tension!.
Given I use my RPR a couple of times most days, they get a fair amount of use.
However, I'm not impressed with how quickly they've become junk..